This invention relates to a torque multiplying wrench and more particularly to a wrench small enough to be hand held and capable of providing large increases in torque with minimum effort by the user.
Many presently available devices for providing high torque lack the ability to induce turning force in the plane of the nut or bolt. Furthermore, many of them suffer from one or more major limitations. In several, these devices are heavy and require bulky stabilizing reaction arms. In addition, many are unable to work around an obstacle such as a pipe or operate in confined spaces, or even reach a nut from the side. Another drawback of existing torque multipliers is their relatively high cost and in many cases the need to have more than one person apply the tool.
Furthermore, new bolting technology is rapidly replacing riveting and welding methods in a variety of construction and engineering industries. Although the evolution of this technology has been rapid, the corresponding development of supporting tools has lagged far behind.
In my U.S. Pat. No. 4,506,567 issued on Mar. 26, 1985 I show a maximum capability wrench which was designed as a hand tool for mechanics, hobbyists, "do-it-yourselfers", and others, to remove, for example a stubborn nut, or to reach in places where the work to be performed does not permit rotation of the wrench itself. While the patented tool has proven to be useful under the particular set of circumstances described, it has turned out not to be adequate for the major applications described above, for a variety of reasons. For these applications, the use of the chain drive produces an inadequate amount of torque multiplication. In addition, no provision is made to deal with the large reaction forces. Also, the patented tool does not permit repairs to be readily made by the user, a feature which might be expected for a small, inexpensive tool useful for relatively light applications. For the kinds of applications concerned about herein, the ability to make repairs in the field is an important advantage.